{
    function fn([a,b]){
        return a+b;
    }
    console.log(fn([1,2]))
}
{
    function fn(){
        return [1,2];
        //1价格 2数量
    }
    let a,b;
    // a=fn()[0];
    // b=fn()[1];
    [a,b]=fn();
    console.log(a,b)
}
{
    function fn(){
        return [1,2,3,4,5,6,7,8];
    }
    let a,b,c;
    [a,,,b,...c]=fn();
    console.log(a,b,c);
}
